Joule-Thomson expansion of AdS black holes in quasi-topological electromagnetism

TL;DR

This paper investigates the Joule-Thomson expansion of AdS black holes within a modified electromagnetism framework, revealing a novel three-branch inversion curve behavior differing from traditional van der Waals models.

Contribution

It introduces the analysis of Joule-Thomson expansion in quasi-topological electromagnetism, uncovering three-branch inversion curves dependent on parameter choices, unlike the typical two-branch structure.

Findings

Discovered three branches in inversion curves for certain parameters.

Mapped cooling and heating regions in temperature-pressure space.

Demonstrated departure from van der Waals behavior in black hole thermodynamics.

Abstract

We study the Joule-Thomson expansion in Einstein-Maxwell theory supplemented with the so-called quasitopological electromagnetism, this in the extended phase space thermodynamic approach. We compute the Joule-Thomson coefficient and depict all relevant inversion and isenthalpic curves in the temperature-pressure plane, determining in this manner the corresponding cooling and heating regions. In contrast with previous related works we show the existence of three branches for the inversion curves which depends on suitable selections of the parameter space of the theory, thus departing from the usual van der Waals behavior which exhibits up to two branches.